CN205219682U - Hollow single screw extruder who has two -sided screw channel - Google Patents

Abstract

The utility model relates to a hollow single-screw extruder with double-sided screw grooves, comprising a motor, a transmission mechanism, a seat, a centripetal thrust bearing group, a barrel, a hollow screw, an electric heating ring, an extruder head, a hopper, Gear and central shaft; wherein the motor drives the hollow screw to rotate through the transmission mechanism and the gear, and the extruder head is set at the discharge end of the barrel; the feature is that the hollow screw is located in the barrel, and the center The shaft is located in the hollow screw, the hollow screw is coaxial with the barrel and the central axis and can be rotated relative to each other. There is an outer spiral groove on the outer surface of the hollow screw, and an inner spiral groove on the inner hole of the hollow screw; The first discharge port and the second discharge port of the hopper communicate with the left ends of the inner spiral groove and the outer spiral groove respectively, and the right ends of the outer spiral groove and the inner spiral groove communicate with the extruder head. It can greatly shorten the length of the screw, fully meet the requirements of the material extrusion process for the relative length of the screw flow channel, reduce the residence time of the material in the screw groove, reduce the decomposition of polymer materials, ensure the quality of the product, and extend the length of the machine. The service life is longer, the productivity of the machine is significantly improved, and the hollow screw with improved thermal efficiency.

Description

Hollow single-screw extruder with double-sided screw channels

technical field

The utility model relates to a novel hollow single-screw extruder with double-sided screw grooves, which is mainly used for mixing, plasticizing and extruding polymer materials, and belongs to the technical field of polymer material molding equipment.

Background technique

Plastic extrusion molding machine is an important equipment for processing polymers. After polymers (granules, powders, etc.) enter the barrel and screw groove space through the hopper, they move forward under the push of the screw flight. Every time the screw rotates, The material moves forward by a lead, and the material has to go through a series of processes such as plasticizing and melting in the screw groove. Its shape changes from the initial solid state to the molten state through many links such as plug flow, molten film, circulation and solid phase crushing. state, and then molded into plastic products through machine heads, molds and other equipment.

Obviously, in a plastic extrusion molding machine, the screw is the most important and core component. Its structure and shape not only affect the quality of processed products, but also affect the service life and energy consumption of the machine. If a traditional single-screw extruder is used to ensure the completion of this series of links, in order to increase the extrusion output, it is often necessary to increase the depth and width of the screw groove. The increase in the depth of the screw groove will reduce the drag of the barrel on the bottom of the screw groove. The dragging effect makes the material at the bottom of the screw groove and the material near the barrel unable to be fully mixed and melted. On the other hand, it will increase the time for the material to completely melt and reach the same temperature; and in order to make all the materials reach the melt conveying section If it can be fully mixed and melted at any time, the length of the screw must be increased. This will not only increase the residence time of the material in the barrel, cause the material to decompose, and affect the quality of the extruded product. At the same time, increasing the length of the screw will also bring A series of problems associated with long screws, such as: insufficient rigidity, poor stability, and severe scraping and friction of the screw to the barrel; other extrusion equipment that uses multi-screw processing, although multi-screw extruders have There are many advantages, but it also brings problems such as complex structure, increased manufacturing and use costs.

There are also some plastic machines that use a hollow screw. After consulting the relevant patent documents, I found the two patents listed below, and found that although they all adopted the "hollow" screw scheme similar to the present invention, their inner cavities have no screw. Grooves are smooth cylinders or conical surfaces, and the mechanism of action is also far from the present invention. The screw rods in these patents all only have screw grooves on the outer surface, and their inner cavity has no screw grooves.

Example 1, the patent "Coaxial Multi-screw Extruder" (publication number CN1059151C) discloses an extruder with multi-screw and multi-sleeve. The extruder described in this patent has two screws, two sleeve, but its two screw rods only have screw grooves on its outer circular surface, and its inner profile has no screw grooves, while its two sleeves have no screw grooves on its inner and outer circular surfaces. Said extruder is equipped with coaxial multi-layer barrel and screw rod, which can extrude the materials of multiple layers of different components wrapped in phase at the same time, which is quite different from the technology of the present invention, and its structure is complex.

Example 2, in the patent "composite co-extrusion conical screw extruder" (publication number CN201721024U), the barrel is equipped with two nested coaxial inner and outer screws. Although the inside of each screw is hollow, the screws have only outer The screw groove has no screw groove on its inner surface, so it is different from the extruder screw structure and working principle of the present invention.

Contents of the invention

The purpose of the utility model is to overcome the deficiencies of the existing technology and provide a simple structure, which can greatly shorten the length of the screw, can fully meet the requirements of the material extrusion process on the relative length of the screw flow channel, and reduce the residence time of the material in the screw groove. The extruder with hollow screw can save time, reduce the decomposition of polymer materials, ensure the quality of products, prolong the service life of the machine, significantly improve the productivity of the machine, and improve the thermal efficiency.

In order to achieve the above purpose, the utility model patent is realized in this way, which is a hollow single-screw extruder with double-sided screw grooves, including a motor, a transmission mechanism, a seat, a centripetal thrust bearing group, a machine barrel, a hollow Screw, electric heating coil, extruder head, hopper, gear and central shaft; wherein the motor drives the hollow screw to rotate through the transmission mechanism and gear, and the extruder head is set at the discharge end of the barrel; its characteristics The hollow screw is located in the barrel, the central axis is located in the hollow screw, the hollow screw is coaxial with the barrel and the central axis and can be rotated relatively, and an outer spiral groove is provided on the outer surface of the hollow screw. The inner circular hole of the hollow screw is provided with an inner spiral groove; the first discharge port and the second discharge port of the hopper are connected with the left end of the inner spiral groove and the outer spiral groove respectively, and the right ends of the outer spiral groove and the inner spiral groove Connect with extruder head.

The left end of the hollow screw is provided with an outer annular groove and a radial feeding channel, and the first outlet of the hopper communicates with the left end of the inner spiral groove through the outer annular groove and the radial feeding channel in sequence.

A group of radial mixing channels is provided on the wall of the hollow screw, and the group of radial mixing channels communicates the inner helical groove with the outer helical groove.

The hollow screw is respectively provided with an outer barrier ring and an inner barrier ring, the outer barrier ring cuts off the outer spiral groove, and the inner barrier ring cuts off the inner spiral groove; the hollow screw is located on both sides of the outer barrier ring Both are provided with a group of radial mixing channels connecting the outer helical groove and the inner helical groove, and both sides of the inner barrier ring on the hollow screw are provided with a group of radial mixing channels connecting the outer helical groove and the inner helical groove.

The hollow screw can be a single-start screw or a multi-start screw.

The screw grooves and ribs of the outer spiral groove and the inner spiral groove can be designed as different cross-sectional profiles, and can also be designed as pins, barrier heads, rings, separation shapes, groove shapes, and waves.

The central axis can be fixed or rotate.

The outer helical groove of the hollow screw rod has the same direction of rotation as the inner helical groove, and the helical direction of the outer helical groove and the inner helical groove of the hollow screw rod can be either left-handed or right-handed.

Compared with the prior art, the utility model has the following advantages:

Since this patent adopts the hollow screw structure with screw grooves in the outer circle and the inner hole, it only needs to use a smaller screw groove depth and width to ensure that the screw has a large screw groove end surface area on the same section to meet the requirements of extrusion. The demand for output greatly reduces the length of the screw, so there are three advantages:

1. The shallow screw groove can strengthen the dragging effect of the barrel on the material, and enhance the turning, mixing, shearing, stretching and melting of the polymer material in the screw groove, so that the material can be fully mixed, homogenized and melted in a short time. Complete melting, the temperature of the material in the screw channel is more likely to be consistent, shorten the residence time of the material in the screw, reduce the decomposition of the material, especially for the processing of temperature-sensitive materials, and ensure the quality of the product;

2. Since the length of the screw is shortened, the inherent rigidity and poor stability of the long screw are eliminated, which can greatly reduce the scraping and friction of the screw on the barrel and prolong the service life of the machine;

3. The structure is simple, which can fully meet the requirements of the material extrusion process for the relative length of the screw runner, and significantly improve the productivity and thermal efficiency of the machine.

Description of drawings

Fig. 1 is the structural representation of the utility model embodiment one;

Fig. 2 is a structural schematic diagram of the cooperation of the extruder head, hopper, barrel, hollow screw and central shaft in Fig. 1;

Fig. 3 is a structural schematic diagram of the coordination of the extruder head, hopper, machine barrel, hollow screw and central shaft in the second embodiment of the present invention;

Fig. 4 is a structural schematic diagram of the coordination of the extruder head, hopper, machine barrel, hollow screw and central shaft in the third embodiment of the utility model.

detailed description

Below in conjunction with accompanying drawing, the specific embodiment of the present utility model will be further described. It should be noted here that the descriptions of these implementations are used to help understand the utility model, but are not intended to limit the utility model. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute conflicts with each other.

In the description of the present utility model, the orientation or positional relationship indicated by the terms "left" and "right" are based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the utility model and does not require that the utility model must be based on Specific orientation configurations and operations, therefore, should not be construed as limitations on the invention.

In the description of the present invention, the terms "first" and "second" are only used for descriptive purposes, and should not be understood as indicating or implying relative importance.

Embodiment one

As shown in Figure 1 and Figure 2, it is a hollow single-screw extruder with double-sided screw grooves, including a motor 1, a transmission mechanism 2, a seat 3, a radial thrust bearing group 4, a barrel 5, a hollow Screw 6, electric heating coil 7, extruder head 8, hopper 9, gear 10 and central shaft 11; wherein the motor 1 drives the hollow screw 6 to rotate through the transmission mechanism 2 and gear 10, and the extruder head 8 Located at the discharge end of the barrel 5; the hollow screw 6 is located in the barrel 5, the central shaft 11 is located in the hollow screw 6, the hollow screw 6 is coaxial with the barrel 5 and the central shaft 11 and can be rotated relatively , an outer helical groove 601 is provided on the outer circular surface of the hollow screw 6, and an inner helical groove 602 is provided on the inner circular hole of the hollow screw 6; the first discharge port 901 and the second discharge port of the hopper 9 902 communicates with the left ends of the inner helical groove 602 and the outer helical groove 601 respectively, and the right ends of the outer helical groove and the inner helical groove communicate with the extruder head 8 .

In this embodiment, in order to better connect the first discharge port 901 with the left end of the inner spiral groove 602, an outer annular groove 603 and a radial feeding channel 604 are provided at the left end of the hollow screw 6, so that The first outlet 901 of the hopper 9 communicates with the left end of the inner spiral groove 602 through the outer annular groove 603 and the radial feeding channel 604 in sequence.

When working, a part of the material enters the left end of the inner spiral groove 602 along the first discharge port 901 of the hopper 9 through the outer annular groove 603 and the radial feeding channel 604, and moves along the inner spiral groove 602 toward the extruder head. The right end of the inner helical groove 602; another part of the material enters the left end of the outer helical groove 601 of the hollow screw along the second outlet 902 of the hopper 9, and moves along the outer helical groove 601 to the extruder head, that is, the outer helical groove 601 The material enters the extruder head at the right end of the outer spiral groove and the right end of the inner spiral groove.

Embodiment two

As shown in Figure 3, it is a hollow single-screw extruder with double-sided screw grooves, including a motor 1, a transmission mechanism 2, a seat 3, a radial thrust bearing group 4, a barrel 5, a hollow screw 6, Electric heating ring 7, extruder head 8, hopper 9, gear 10 and central shaft 11; wherein the motor 1 drives the hollow screw 6 to rotate through the transmission mechanism 2 and the gear 10 (not shown in Fig. 3, its matching relationship Same as Embodiment 1), the extruder head 8 is located at the discharge end of the barrel 5; the hollow screw 6 is located in the barrel 5, the central axis 11 is located in the hollow screw 6, and the hollow screw 6 and The barrel 5 and the central shaft 11 are coaxial and can be rotated relative to each other. An outer helical groove 601 is provided on the outer surface of the hollow screw 6, and an inner helical groove 602 is provided on the inner hole of the hollow screw 6; the hopper The first discharge port 901 and the second discharge port 902 of 9 communicate with the left end of the inner spiral groove 602 and the outer spiral groove 601 respectively, and the right ends of the outer spiral groove and the inner spiral groove communicate with the extruder head 8; A group of radial mixing channels 605 is provided on the wall of the hollow screw 6 , and the group of radial mixing channels 605 communicates the inner helical groove 602 with the outer helical groove 601 .

In this embodiment, in order to better connect the first discharge port 901 with the left end of the inner spiral groove 602, an outer annular groove 603 and a radial feeding channel 604 are provided at the left end of the hollow screw 6, so that The first outlet 901 of the hopper 9 communicates with the left end of the inner spiral groove 602 through the outer annular groove 603 and the radial feeding channel 604 in sequence.

When working, a part of the material enters the left end of the inner spiral groove 602 along the first discharge port 901 of the hopper through the outer annular groove 603 and the radial feeding channel 604, and moves along the inner spiral groove 602 to the direction of the extruder head. Part of the material enters the outer spiral groove 601 along the second outlet 902 of the hopper 9. When moving along the outer spiral groove 601 to the radial mixing channel group 605, a split flow will occur, and part of the material will continue to be extruded along the outer spiral groove 601. When moving in the direction of the machine head, another part of the material enters the inner spiral groove 602 along the radial mixing channel group 605 and forms a "confluence" with the material in the inner spiral groove 602, and moves along the inner spiral groove 602 to the direction of the extruder head; When the material in the inner helical groove 602 reaches the next radial mixing channel group 605, a split flow occurs again, part of the material continues to move along the inner helical groove 602 toward the extruder head, and the other part of the material will move along the radial mixing channel group 605 Enter the outer helical groove 601 and form a "confluence" with the material in the outer helical groove 601, and continue to move along the outer helical groove 601 to the direction of the extruder head; finally, the materials in the outer helical groove 601 and the inner helical groove 602 converge together in the Extrusion head 8.

Embodiment three

As shown in Figure 4, it is a hollow single-screw extruder with double-sided screw grooves, including a motor 1, a transmission mechanism 2, a seat 3, a radial thrust bearing group 4, a barrel 5, a hollow screw 6, Electric heating ring 7, extruder head 8, hopper 9, gear 10 and central shaft 11; wherein the motor 1 drives the hollow screw 6 to rotate through the transmission mechanism 2 and the gear 10 (not shown in Fig. 4, its matching relationship Same as Embodiment 1), the extruder head 8 is located at the discharge end of the barrel 5; the hollow screw 6 is located in the barrel 5, the central axis 11 is located in the hollow screw 6, and the hollow screw 6 and The barrel 5 and the central shaft 11 are coaxial and can be rotated relative to each other. An outer helical groove 601 is provided on the outer surface of the hollow screw 6, and an inner helical groove 602 is provided on the inner hole of the hollow screw 6; the hopper The first discharge port 901 and the second discharge port 902 of 9 communicate with the left end of the inner spiral groove 602 and the outer spiral groove 601 respectively, and the right ends of the outer spiral groove and the inner spiral groove communicate with the extruder head 8; The hollow screw 6 is respectively provided with an outer barrier ring 606 and an inner barrier ring 607, the outer barrier ring 606 isolates the outer spiral groove 601, and the inner barrier ring 607 isolates the inner spiral groove 602; Both sides of the barrier ring 606 are provided with a radial mixing channel group 605 connecting the outer spiral groove 601 and the inner spiral groove 602, and the hollow screw 6 is located on both sides of the inner barrier ring 607. The radial mixing channel group 605 of the inner spiral groove 602 .

In this embodiment, an outer annular groove 603 and a radial feeding channel 604 are provided on the left end of the hollow screw 6, and the first outlet 901 of the hopper 9 passes through the outer annular groove 603 and the radial feeding channel 604 sequentially. The feed channel 604 communicates with the left end of the internal spiral groove 602 .

When working, a part of the material enters the left end of the inner spiral groove 602 along the first discharge port 901 of the hopper through the outer annular groove 603 and the radial feeding channel 604, and moves along the inner spiral groove 602 to the direction of the extruder head. A part of the material enters the outer spiral groove 601 along the second discharge port 902 of the hopper 9. When the material moves to the outer barrier ring 606 along the outer spiral groove 601, it is blocked by it and cannot continue to move along the outer spiral groove 601, but along the outer spiral groove 601. Enter the inner spiral groove 602 to the mixing channel group 605. At this time, the two streams from the inner and outer spiral grooves "merge" for the first time, and continue to move toward the extruder head along the inner spiral groove 602, and then enter the inner spiral groove to the right. In the next section of the spiral groove 602, some materials will be diverted to the outer spiral groove 601 along the radial mixing channel group 605, and the rest of the materials will continue to move along the inner spiral groove 602 to the extruder head; when the material in the inner spiral groove 602 When it moves to the inner barrier ring 607, it will enter the outer spiral groove 601 along another radial mixing channel group 605 and "merge" with the material in the outer spiral groove 601 again, and continue to move towards the direction of the extruder head. Then, the outer The material in the spiral groove 601 is "divided" again, part of the material continues to move along the outer spiral groove 601 to the direction of the extruder head, and the other part of the material will re-enter the inner spiral groove 602 along another radial mixing channel group 605 and continue to extrude The machine head moves in the direction, and finally, the materials in the outer helical groove 601 and the inner helical groove 602 converge on the extruder head 8 together.

In Embodiment 1 to Embodiment 3, the hollow screw 6 may be a single-start screw or a multi-start screw. The screw grooves and ribs of the outer spiral groove and the inner spiral groove can be designed as different cross-sectional profiles, and can also be designed as pins, barrier heads, rings, separation shapes, groove shapes, and waves. The central shaft 11 can be fixed or rotate. The outer helical groove of the hollow screw 6 and the inner helical groove have the same direction of rotation, and the outer helical groove of the hollow screw 6 and the inner helical groove can be either left-handed or right-handed. The electric heating ring 7 is set outside the machine barrel 5 to speed up the melting of the material in the outer spiral groove 601, and the heating device in the central mandrel 11 heats the mandrel 11 and the material. Since the electric heating technology is relatively mature and not the focus of this patent, Therefore, the electrothermal device is not shown on the mandrel 11 .

The embodiments of the present utility model have been described in detail above in conjunction with the accompanying drawings, but the present utility model is not limited to the described embodiments. For those skilled in the art, various changes, modifications, replacements and deformations to these embodiments without departing from the principle and purpose of the present invention still fall within the protection scope of the present invention.

Claims (8)

1. A hollow single-screw extruder with double-sided screw grooves, including a motor (1), a transmission mechanism (2), a seat (3), a radial thrust bearing group (4), a barrel (5), Hollow screw (6), electric heating coil (7), extruder head (8), hopper (9), gear (10) and central shaft (11); wherein the motor (1) passes through the transmission mechanism (2) and The gear (10) drives the hollow screw (6) to rotate, and the extruder head (8) is set at the discharge end of the barrel (5); it is characterized in that the hollow screw (6) is located ), the central shaft (11) is located in the hollow screw (6), the hollow screw (6) is coaxial with the barrel (5) and the central shaft (11) and can be rotated relative to each other, and the hollow screw (6) An outer helical groove (601) is provided on the outer surface, and an inner helical groove (602) is provided on the inner hole of the hollow screw (6); the first outlet (901) and the second outlet of the hopper (9) The two outlets (902) communicate with the left ends of the inner helical groove (602) and the outer helical groove (601) respectively, and the right ends of the outer helical groove and the inner helical groove communicate with the extruder head (8). 2. The hollow single-screw extruder with double-sided screw grooves according to claim 1, characterized in that the left end of the hollow screw (6) is provided with an outer annular groove (603) and a radial feeding channel (604), the first outlet (901) of the hopper (9) communicates with the left end of the inner spiral groove (602) through the outer annular groove (603) and the radial feeding channel (604) sequentially. 3. The hollow single-screw extruder with double-sided screw grooves according to claim 1, characterized in that a radial mixing channel group (605) is provided on the wall of the hollow screw (6), the The radial mixing channel group (605) connects the inner spiral groove (602) with the outer spiral groove (601). 4. The hollow single-screw extruder with double-sided screw grooves according to claim 1, characterized in that an outer barrier ring (606) and an inner barrier ring (607) are respectively provided on the hollow screw (6) , the outer barrier ring (606) isolates the outer spiral groove (601), and the inner barrier ring (607) isolates the inner spiral groove (602); on the hollow screw (6), the outer barrier ring (606) Both sides are equipped with a radial mixing channel group (605) connecting the outer spiral groove (601) and the inner spiral groove (602). A group of radial mixing channels (605) connecting the outer spiral groove (601) and the inner spiral groove (602). 5. The hollow single-screw extruder with double-sided screw grooves according to claim 1 or 2 or 3 or 4, characterized in that the hollow screw (6) can be a single-start screw or a multi-start screw. 6. The hollow single-screw extruder with double-sided screw grooves according to claim 1, characterized in that the screw grooves and flight edges of the outer spiral groove (601) and the inner spiral groove (602) can be designed to be different The cross-section profile can also be designed as pins, barrier heads, rings, split shapes, groove shapes, and waves. 7. The hollow single-screw extruder with double-sided screw grooves according to claim 1, characterized in that the central shaft (11) can be fixed or rotated. 8. The hollow single-screw extruder with double-sided screw grooves according to claim 1 or 2 or 3 or 4, characterized in that the outer spiral groove of the hollow screw (6) is in the same direction as the inner spiral groove, The direction of rotation of the outer helical groove (601) and the inner helical groove (602) of the hollow screw (6) can be either left-handed or right-handed.